There have been rumors, and some convincing photos, from Europe, indicating some amelanistic D. couperi were hatched about 13 years ago, but nothing since.
The idea of a color morph among Drymarchon spp. causes concern among most people working with the genus, especially in regards to D. couperi and D. m erebennus, as such anomalies can indicate other genetic problems. Most feel the last thing D. couperi need; are to be produced for a genetic defect, as the gene pool is already limited enough, without the inbreeding pressure placed upon the captive production of color morphs.
In short, most deem it unwise to attempt color morph production of a species on the threatened and / or endangered species list. This probably would not be such an issue regarding any of the Cribos, though I am unaware of any phenotypic color morphs regarding them and I do not know of anyone who has knowledge of such…
Best regards,
Jeff
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Jeff Snodgres
University of Arkansas
snodgresjeffreys@uams.edu
501.603.1947